1. Field of the Invention
The present invention relates to a speaker and a speaker unit having the speaker mounted on a vehicle such as a motor vehicle and a vessel.
2. Description of the Related Art
The vehicle such as the motor vehicle and vessel is equipped with a speaker to output various types of sound information, for example, refer to JP,2004-187173,A. The speaker includes a case to be attached to a structure, a magnetic circuit received in the case, and a diaphragm for generating sound driven by the magnetic circuit. A signal current is supplied to a voice coil disposed in a magnetic gap so as to vibrate the diaphragm and generate sound.
The conventional speaker has a chamber therein, which vibrates the air vibrated with the diaphragm, to achieve a desired sound characteristics. JP,2004-187173,A discloses that the chamber is disposed behind the diaphragm and overlapped with the diaphragm and the magnetic circuit along an axis thereof.
When the chamber is disposed in the speaker, the speaker becomes thick along a direction of thickness. The case including the speaker becomes large and is not appreciated for attaching to the structure.